The disclosed invention is directed generally to RF excited gas discharge lights sources, and more particularly to a shrouded pin electrode structure for RF excited gas discharge light sources.
RF gas discharge light sources generally include a gas containment vessel or envelope, and an electrode structure for coupling RF energy into the discharge gas in the containment vessel. The electrode structure is driven by an RF source, and generates a magnetic or electric field that excites the gas molecules. The excited gas molecules emit photons as drop to state(s) with lower energy.
Electrode structures utilized in RF gas discharge light sources commonly comprise pins that are located internal to the gas containment vessel and exposed to the contained gas. The primary energy transfer mechanism involves the acceleration/deceleration of electrons which are thermonically excited off the electrode surface.
Considerations with the use of internal pin electrodes include the use of a glass to metal seal which is susceptible to manufacturing defects, as well as failure and leakage during use, particularly in environments with significant vibration or rapid thermal transitions. Also, electrode material can easily contaminate the discharge gas.